The key difference between p38 MAPK and ERK is that p38 MAPK is a protein kinase that is responsive to stimuli such as cytokines, ultraviolet irradiation, heat shock, and osmotic shock, while ERK is a protein kinase that is responsive to stimuli such as growth factors, cytokines, virus infection, ligands for heterotrimeric G protein-coupled receptors, transforming agents, and carcinogens.
p38 MAPK and ERK are two different protein kinases involved in the important signaling pathways in the human body. p38 MAPK is involved in the p38 MAPK pathway, while ERK is involved in the ERK pathway. Moreover, p38 MAPK is important in regulating cell differentiation, apoptosis, and autophagy, whereas ERK is important in regulating meiosis, mitosis, and postmitotic functions in differentiated cells.
CONTENTS
1. Overview and Key Difference
2. What is p38 MAPK
3. What is ERK
4. Similarities – p38 MAPK and ERK
5. p38 MAPK vs. ERK in Tabular Form
6. Summary – p38 MAPK vs. ERK
What is p38 MAPK?
p38 mitogen-activated protein kinase (p38 MAPK) is a protein involved in the p38 MAPK pathway. This protein is responsive to stress stimuli, such as cytokines, ultraviolet irradiation, heat shock, and osmotic shock. It is involved in regulating cell differentiation, apoptosis, and autophagy. There are four p38 MAP kinases: p38-α (MAPK14), -β (MAPK11), -γ (MAPK12 / ERK6), and -δ (MAPK13 / SAPK4). In the p38 MAPK pathway, different protein kinases such as MKK3 and SEK activate p38 MAP kinase by phosphorylation at Threonine 180 and Tyrosine 182 positions.
The activated p38MAPK later phosphorylates and activates the MAPKAP kinase 2 protein. It also phosphorylates the transcription factors ATF2, Mac, MEF2, and p53. Moreover, p38MAPK can also phosphorylate post-transcriptional regulating factors like TTP. However, the persistent activation of the p38 MAPK pathway in muscle satellite cells due to ageing can impair muscle regeneration. In addition, excessive activation of this protein is also involved in cancer cell survival and metastasis.
What is ERK?
ERK is a protein kinase that is also known as extracellular signal-regulated kinase or classical MAP kinase. ERK1 and ERK2 are the most common and widely studied isoenzymes of ERK. This protein is responsive to stimuli such as growth factors, cytokines, virus infection, ligands for heterotrimeric G protein-coupled receptors, transforming agents, and carcinogens. Moreover, ERK is important in regulating meiosis, mitosis, and postmitotic functions in differentiated cells.
In the ERK pathway, the Ras protein activates c-Raf protein kinase, followed by mitogen-activated protein kinase (MAP2K) and then MAPK1/2 (ERK1). Growth hormones generally activate Ras protein through receptor tyrosine kinases and GRB2/SOS. ERK protein activates many transcription factors like ELK1 and some other downstream protein kinases. In addition, disruption of the ERK pathway is common in cancers.
What are the Similarities Between p38 MAPK and ERK?
- p38 MAPK and ERK are two different protein kinases.
- Both are made up of amino acids and are involved in cellular signaling pathways.
- Both can control cell cycle processes.
- The aberrant expression of both can cause cancers.
What is the Difference Between p38 MAPK and ERK?
p38MAPK is a protein kinase that is responsive to stimuli such as cytokines, ultraviolet irradiation, heat shock, and osmotic shock, while ERK is a protein kinase that is responsive to stimuli such as growth factors, cytokines, virus infection, ligands for heterotrimeric G protein-coupled receptors, transforming agents, and carcinogens. Thus, this is the key difference between p38 MAPK and ERK. Furthermore, p38 MAPK is important in regulating cell differentiation, apoptosis, and autophagy. On the other hand, ERK is important in regulating meiosis, mitosis, and postmitotic functions in differentiated cells.
The infographic below presents the differences between p38 MAPK and ERK in tabular form for side-by-side comparison.
Summary – p38 MAPK vs ERK
There are different signal transduction pathways in the human body that regulates cell division, differentiation, and growth. p38 MAPK pathway and ERK pathway are two different signaling pathways. p38 MAPK participates in the p38 MAPK pathway, while ERK is a protein kinase that participates in the ERK pathway. p38MAPK is activated by stimuli such as cytokines, ultraviolet irradiation, heat shock, and osmotic shock, while ERK is activated by stimuli such as growth factors, cytokines, virus infection, ligands for heterotrimeric G protein-coupled receptors, transforming agents, and carcinogens. Moreover, p38 MAPK is important in regulating cell differentiation, apoptosis, and autophagy, whereas ERK is important in regulating meiosis, mitosis, and postmitotic functions in differentiated cells. So, this summarizes the difference between p38 MAPK and ERK.
Reference:
1.“Extracellular Signal-Regulated Kinases – An Overview.” ScienceDirect Topic.
2. Asih, Prita R., et al. “Functions of P38 MAP Kinases in the Central Nervous System.” Frontiers.
Image Courtesy:
1. “Egfr-erk pathway” By Yuji Miyamoto, Koichi Suyama and Hideo Baba – MDPI (CC BY-SA 4.0) via Commons Wikimedia